If all gun sales must be done using and FFL in Ca since 1991 (The gun was a 1998) , and they are so strict about everything in this state, why no one cares if the seller is the owner?

You are expecting the government to make sense? :-)

They seem to care more about it being recorded than to do something about how it was done. If the government went after people for "selling" a firearm that was not recorded that they owned, then the people would stop doing the transfer.

Also, they don't really have good records of who owns what. If the firearm was sold before the law was put in place that all transfers have to go through a FFL, then it could have been legally sold to another person. This means it would take a lot to determine if the seller was not actually the seller or not.